Electronic device and a method of manufacturing the same

ABSTRACT

A method of manufacturing an electronic device including a first electronic component mounted on one main surface of a wiring board by being thermo-compression bonded by means of a thermo-compression bonding tool with an adhesive resin interposed between a first area of the one main surface of the wiring board and the first electronic component, and a second electronic component mounted on a second area different from the first area of the one main surface of the wiring board by melting a soldering paste material and higher than the first electronic component in post-mounting height, and wherein the first electronic component is mounted before the mounting of the second electronic component.

FIELD OF THE INVENTION

[0001] The present invention relates to an electronic device and amanufacturing technology thereof, and particularly to a technologyeffective for application to an electronic device having electroniccomponents mounted on a wiring board, which is suitable for use in eachof different embodiments.

BACKGROUND OF THE INVENTION

[0002] There has been known an electronic device called an “MCM (MultiChip Module)” as an electronic device. The MCM is one wherein aplurality of semiconductor chips each having an integrated circuit builttherein are mounted or implemented on a wiring board to configure oneintegrated function. In order to speed up a data transfer rate of theMCM and downsize it, a flip-chip mounting technology for usingsemiconductor chips (flip chips) wherein protruded electrodes arerespectively formed on electrode pads placed on a circuit formingsurface, and mounting the same on a wiring board has actively beenadopted for the MCM.

[0003] In the flip-chip mounting technology, various mounting orpackaging methods or systems have been proposed and put into practicaluse. As one of them, there is known an ACF mounting or packaging systemusing a sheet-like anisotropic conductive film (ACF: AnisotropicConductive Film) as an adhesive resin. The ACF mounting system is amethod for using a semiconductor chip wherein stud bumps eachcomprising, for example, gold (Au) are respectively formed on electrodepads placed on a circuit forming surface as protruded electrodes,thermo-compression bonding the semiconductor chip in a state in which anACF resin is being interposed between the semiconductor chip and awiring board to thereby bond and fix the semiconductor chip to thewiring board, and electrically connecting connecting portions of wiringsof the wiring board and electrode pads of the semiconductor chiprespectively. The anisotropic conductive film is one obtained by mixinglots of conductive particles into an insulating-film resin in dispersedform. The ACF mounting has been described in Unexamined PatentPublication Hei No. 10(1998)-270496 (U.S. Pat. No. 6,208,525).

[0004] In addition to the ACF mounting system, there are known an NCFmounting system using a sheet-like non conductive film (NCF: NonConductive Film) as an adhesive resin, an ACP mounting system using apaste-like anisotropic conductive resin (ACP: Anisotropic ConductivePaste) as an adhesive resin, etc.

[0005] On the other hand, soldering devices or electronic componentsmounted or packaged by soldering are known as surface mount devices(SMD: Surface Mount Devices) mounted on a wiring board in addition tothe semiconductor chip. The soldering electronic components includepassive components or parts and active components or parts. As thesoldering passive components, may be mentioned, for example, chipcapacitors, chip resistors, chip inductors, etc. As the soldering activecomponents, may be mentioned, for example, semiconductor devices such asa BGA (Ball Grid array) type, a CSP (Chip Size Package) type, a QFP(Quad Flatpack Package) type, a QFN (Quad Flatpack Non-Leaded Package)type, which respectively include packaged semiconductor chips, etc.

SUMMARY OF THE INVENTION

[0006] Meanwhile, the present inventors have developed an MCM wherein asemiconductor chip (hereinafter called a “compression mounted IC(Integrated Circuit) chip”) mounted by thermo-compression bonding as inthe ACG mounting system, and soldering electronic components are placedon the same wiring board in mixed form. Upon the development of thepresent MCM, the present inventors have found out the followingproblems.

[0007] (1) The soldering electronic components include those whosepost-mount heights (each corresponding to a height from one main surfaceof a wiring board to the top portion) are higher than that of thecompression mounted IC chip. When such soldering electronic componentshigh in height are mounted prior to the compression mounted IC chip, athermo-compression bonding tool (thermo-compression bonding head) forthermo-compression bonding the compression mounted IC chip become easyto contact the already-mounted soldering electronic components uponmounting the compression mounted IC chip. It is therefore necessary towiden the interval between each soldering electronic component and itscorresponding compression mounted IC chip. Further, this would lead tothe inhibition of a size reduction in MCM.

[0008] When it is desired to collectively thermo-compression bond aplurality of compression mounted IC chips with a view toward improvingproductivity, it is necessary to use one larger than the compressionmounted IC chip as a thermo-compression bonding tool. However, whensoldering electronic components high in height exist within a range forthe thermo-compression bonding tool, it becomes difficult tocollectively thermo-compression bond the IC chips.

[0009] (2) A soldering paste material (corresponding to a semisolidsoldering material obtained by mixing and kneading lots of solderparticles and flux together) is supplied to connecting portions ofwirings for the wiring board, soldering electronic components arethereafter mounted so that the connecting portions of the wirings forthe wiring board and their corresponding electrode portions of thesoldering electronic components are held face to face with one anotherwith the soldering paste material interposed therebetween, andsubsequently they are subjected to heat treatment to thereby melt thesoldering paste material, whereby the mounting of the solderingelectronic components is carried out. For the purpose of the supply ofthe soldering paste material, a screen printing method or a dispensemethod is used. The screen printing method is a method for transferringa soldering paste material placed on a screen mask to the surface of asubstrate through each aperture or opening defined in the screen mask bymeans of a squeegee. The dispense method is a method for discharging asoldering paste material through a thin nozzle and applying it.

[0010] The screen printing method capable of collectively supplying thesoldering paste material is suitable for the achievement of animprovement in productivity of the MCM. However, when the compressionmounted IC chip is mounted prior to each soldering electronic component,it is difficult to supply the soldering paste material by means of thescreen printing method upon the mounting of the soldering electroniccomponents. The supply of the soldering paste material is carried outthrough the use of a screen mask called an “embossed mask” provided withat least one protruded portion at a portion of the already-mountedcompression mounted IC chip so as to avoid the portion, whereby thesupply of the soldering paste material by one operation is allowed. Insuch a case, however, it is necessary to set a plane size of theprotruded portion of the embossed mask larger than that of thecompression mounted IC chip to thereby produce a smooth protruded shapeso that the squeegee can be slid smoothly. Therefore, the solderingelectronic components cannot-be placed in the neighborhood of thecompression mounted IC chip, thereby leading to the inhibition of a sizereduction in MCM.

[0011] (3) A radiator is selected for the MCM which needs to have highdissipation. Since the back of the compression mounted IC chip, which isopposite to its circuit forming surface, is kept bare, the radiator ismounted onto the back of the compression mounted IC chip with a thermalconductive sheet interposed therebetween, the compression mounted ICchip can obtain a high radiating effect. However, when the solderingelectronic components higher than the compression mounted IC chip inpost-mount height exist, the soldering electronic components interferewith the contact between the back of the compression mounted IC chip andthe thermal conductive sheet, whereby the dissipation of the MCM isreduced.

[0012] An object of the present invention is to provide a technologycapable of achieving an improvement in productivity of an electronicdevice.

[0013] Another object of the present invention is to provide atechnology capable of achieving a size reduction in electronic device.

[0014] A further object of the present invention is to provide atechnology capable of achieving an improvement in dissipation of anelectronic device.

[0015] The above, other objects, and novel features of the presentinvention will become apparent from the description of the presentspecification and the accompanying drawings.

[0016] Summaries of typical ones of the inventions disclosed in thepresent application will be described in brief as follows:

[0017] (1) There is provided a method of manufacturing an electronicdevice including a first electronic component mounted on one mainsurface of a wiring board by being thermo-compression bonded by means ofa thermo-compression bonding tool with an adhesive resin interposedbetween a first area of the one main surface of the wiring board and thefirst electronic component, and a second electronic component mounted ona second area different from the first area of the one main surface ofthe wiring board by melting a soldering paste material and higher thanthe first electronic component in post-mounting height, and wherein thefirst electronic component is mounted before the mounting of the secondelectronic component.

[0018] (2) In the method described in the above means (1), the adhesiveresin is a thermosetting resin.

[0019] (3) In the method described in the above means (1), thetemperature of the thermo-compression bonding tool at the time that thefirst electronic component is thermo-compression bonded, is higher thana melting point of the soldering paste material.

[0020] (4) In the method described in the above means (1), the firstelectronic component is an active part with circuits built therein, andthe second electronic component is a passive part.

[0021] (5) There is provided a method of manufacturing an electronicdevice including a first electronic component mounted on one mainsurface of a wiring board by being thermo-compression bonded by means ofa thermo-compression bonding tool with an adhesive resin interposedbetween a first area of the one main surface of the wiring board and thefirst electronic component, and a second electronic component mounted ona second area different from the first area of the one main surface ofthe wiring board by melting a soldering paste material, and wherein thesecond electronic component is mounted before the mounting of the firstelectronic component.

[0022] (6) In the method described in the above means (5), the supply ofthe soldering paste material is carried out by a screen printing method.

[0023] (7) In the method described in the above means (5), the secondelectronic component is higher than the first electronic component inpost-mounting height.

[0024] (8) In the method described in the above means (5), the firstelectronic component is a passive part with circuits built therein, andthe second electronic component is an active part.

[0025] (9) There is provided an electronic device comprising:

[0026] a wiring board;

[0027] a plurality of first electronic components implemented in a firstarea of one main surface of the wiring board;

[0028] a plurality of second electronic components implemented in asecond area different from the first area of the one main surface of thewiring board, and each having a height extending from the one mainsurface of the wiring board to the top portion, which is higher thanthat of each first electronic component; and

[0029] a thermal conductive sheet mounted to the plurality of firstelectronic components and dismounted to the plurality of secondelectronic components.

[0030] (10) In the electronic device described in the above means (9), aradiator mounted to the thermal conductive sheet and formed in a flatsize for covering the plurality of first electronic components and theplurality of second electronic components is provided.

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] While the specification concludes with claims particularlypointing out and distinctly claiming the subject matter which isregarded as the invention, it is believed that the invention, theobjects and features of the invention and further objects, features andadvantages thereof will be better understood from the followingdescription taken in connection with the accompanying drawings in which:

[0032]FIG. 1 is a typical plan view of an MCM (electronic device)showing a first embodiment of the present invention;

[0033]FIG. 2 is a typical bottom view of the MCM shown in FIG. 1;

[0034]FIG. 3 is a cross-sectional view illustrating the state ofmounting of a control chip, buffer chips and chip capacitors built inthe MCM shown in FIG. 1;

[0035]FIG. 4(A) and FIG. 4(B) are cross-sectional views for describingthe manufacture of the MCM showing the first embodiment of the presentinvention;

[0036]FIG. 5(A) and FIG. 5(B) are cross-sectional views for describingthe manufacture of the MCM illustrating the first embodiment of thepresent invention;

[0037]FIG. 6(A) and FIG. 6(B) are cross-sectional views for describingthe manufacture of the MCM depicting the first embodiment of the presentinvention;

[0038]FIG. 7(A) and FIG. 7(B) are cross-sectional views for describingthe manufacture of the MCM illustrating the first embodiment of thepresent invention;

[0039]FIG. 8 is a plan view for describing the manufacture of the MCMshowing the first embodiment of the present invention;

[0040]FIG. 9 is a plan view for describing the manufacture of the MCMillustrating the first embodiment of the present invention;

[0041]FIG. 10(A) and FIG. 10(B) are cross-sectional views for describingthe manufacture of an MCM showing a second embodiment of the presentinvention;

[0042]FIG. 11(A) and FIG. 11(B) are cross-sectional views for describingthe manufacture of the MCM illustrating the second embodiment of thepresent invention;

[0043]FIG. 12(A) and FIG. 12(B) are cross-sectional views for describingthe manufacture of the MCM depicting the second embodiment of thepresent invention;

[0044]FIG. 13(A) and FIG. 13(B) are cross-sectional views for describingthe manufacture of the MCM showing the second embodiment of the presentinvention;

[0045]FIG. 14(A) and FIG. 14(B) are cross-sectional views for describingthe manufacture of the MCM illustrating the second embodiment of thepresent invention;

[0046]FIG. 15 is a cross-sectional view for describing the manufactureof the MCM showing the second embodiment of the present invention;

[0047]FIG. 16 is a plan view for describing the manufacture of the MCMdepicting the second embodiment of the present invention;

[0048]FIG. 17 is a plan view for describing the manufacture of the MCMillustrating the second embodiment of the present invention;

[0049]FIG. 18 is a cross-sectional view showing a schematicconfiguration of an MCM illustrative of a third embodiment of thepresent invention;

[0050]FIG. 19 is a developed view of the MCM shown in FIG. 18;

[0051]FIG. 20 is a developed view of the MCM shown in FIG. 18; and

[0052]FIG. 21 is a cross-sectional view of an MCM to which the presentinvention is not applied.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0053] Preferred embodiments of this invention will hereinafter bedescribed in detail with reference to the accompanying drawings.

[0054] Incidentally, ones each having the same function in all drawingsfor describing the embodiments of the invention are respectivelyidentified by the same reference numerals and their repetitivedescription will therefore be omitted.

[0055]FIG. 1 is a typical plan view of an MCM (electronic device)showing a first embodiment of the present invention. FIG. 2 is a typicalbottom view of the MCM shown in FIG. 1. FIG. 3 is a typicalcross-sectional view showing the state of mounting or implementation ofchip capacitors, a control chip, and buffer chips built in the MCM shownin FIG. 1. Incidentally, hatching indicative of a section is omitted inFIG. 3 to make it easy to see the drawings.

[0056] As shown in FIGS. 1 and 2, an MCM (electronic device) 1 accordingto the present embodiment has a configuration wherein a plurality ofsoldering parts or components and crimped IC chips are placed on onemain surface 2X of a wiring board 2, and a plurality of ball-shapedsolder bumps 22 are disposed on a reverse side or back (the other mainsurface) 2Y thereof opposite to the main surface 2X of the wiring board2 as external connecting terminals. One semiconductor chip (hereinaftercalled a “control chip”) 10 having a control circuit built therein, foursemiconductor chips (hereinafter called “memory chips”) 12 each having amemory circuit (e.g., SDRAM: Synchronous Dynamic Random Access Memory)built therein, five semiconductor chips (hereinafter called “bufferchips”) 14 each having a buffer circuit built therein, and onesemiconductor chip (hereinafter called an “operation or arithmeticchip”) 16 having an NAND circuit built therein are used as the crimpedIC chips. These compression mounted electronic parts or components aremounted or packaged by an ACF packaging system. A plurality of chipcapacitors (17, 18) and chip resistors 19 are used as solderingelectronic parts or components. These soldering electronic componentsare mounted by a soldering reflow method.

[0057] The solder bumps 22 are respectively formed of a solder materialhaving a Pb—Sn composition, for example. The solder bumps 22 areelectrically and mechanically connected to their corresponding electrodepads placed on the back 2Y of the wiring board 2.

[0058] The planar shapes of the control chip 10, memory chips 12, bufferchips 14 and an operation chip 16 are respectively formed in a squarefashion. In the present embodiment, the buffer chips 14 and the memorychips 12 are respectively shaped in the form of a rectangle, forexample, whereas the control chip 10 and the operation chip 16 arerespectively shaped in the form of a square, for example.

[0059] Although not limited to the control chip 10, memory chips 12,buffer chips 14 and operation chip 16, they are respectively configuredso as to principally have a semiconductor substrate, a multilayerinterconnection layer formed by laminating an insulating layer and awiring layer on a circuit forming surface of the semiconductor substratein plural stages, and a surface protective film (final protection)formed so as to cover the multilayer interconnection layer. Thesemiconductor substrate is formed of a monocrystal silicon, for example,the insulating layer is formed of a silicon oxide film, for example, andthe wiring layer is formed of a metal film such as aluminum (Al) or analuminum alloy or the like. A surface protective film for each memorychip 12 is formed of a polyimide resin capable of achieving animprovement in alpha ray-resistant strength to a memory, for example. Asurface protective film for each of the control chip 10, buffer chips 14and operation chip 16 is formed of an insulating film such as siliconoxide or silicon nitride.

[0060] Although not illustrated in detail, the wiring board 2 isconfigured so as to have a rigid substrate, a flexible layer formed onthe rigid substrate by a build-up process, and an insulating film 5formed on the flexible layer. The rigid substrate and flexible layer areformed as a multilayer interconnection structure. Each of insulatinglayers for the rigid substrate is formed of, for example, a high elasticresin plate obtained by impregnating a glass fiber with an epoxy orpolyimide resin. Each of insulating layers for the flexible layer isformed of an epoxy low elastic resin. Further, respective wiring layersfor the rigid substrate and flexible layer are respectively formed of ametal film which comprises copper (Cu), for example. The insulating film5 is formed of an epoxy resin, for example. The insulating film 5 servesso as to control the spread of on-mounting solder leakage to thesoldering electronic components (17, 18 and 19 in the presentembodiment) and ensure adhesion power of an adhesive or bonding rein atpackage with respect to the compression mounted electronic parts orcomponents (10, 12, 14 and 16 in the present embodiment).

[0061] A plurality of connecting portions 3 and electrode pads 4 bothcomprising portions of wirings formed in the wiring layer correspondingto the top layer of the wiring board 2 are provided in the wiring layer.These connecting portions 3 and electrode pads 4 are respectivelyexposed from the one main surface 2X of the wiring board 2 throughapertures or opening defined in the insulating film 5.

[0062] In the control chip 10 and each buffer chip 14, as shown in FIG.3, a plurality of electrode pads (10 a and 14 a) are formed on theircorresponding circuit forming surfaces (10X and 14X) respectivelycorresponding to one main surfaces of one main surfaces and other mainsurfaces opposite to one another, of the respective chips. The pluralityof electrode pads (10 a and 14 a) of the respective chips are formed intheir corresponding wiring layers corresponding to the top layers of themultilayer interconnection layers for the respective chips. They areexposed from their corresponding circuit forming surfaces of therespective chips through bonding openings or apertures defined in thesurface protective films of the respective chips. Although notillustrated in the drawing, a plurality of electrode pads are formed ontheir corresponding circuit forming surfaces of the memory and operationchips 12 and 16 even in the case of both chips in a manner similar tothe control chip 10 and the buffer chips 14. The electrode pads 10 a ofthe control chip 10, the electrode pads 14 a of the buffer chip 14 andthe electrode pads of the operation chip 16 are disposed in a four-sidepad arrangement, and the electrode pads of each memory chip 12 areprovided in a center-pad arrangement.

[0063] Stud bumps 11 made up of, for example, Au are respectively formedon the electrode pads of the control chip 10 and the buffer chips 14 andthe electrode pads of the memory chips 12 and the operation chip 16 asprotruded electrodes at the stage preceding a mounting process. The studbumps 11 are formed by, for example, a ball bonding method of utilizingultrasonic vibrations in combination with thermo-compression bondingthrough the use of Au wires, for example. The present ball bondingmethod is a method of forming balls at leading ends of the Au wires,thereafter thermo-compression bonding the balls to their correspondingelectrode pads of each chip while the ultrasonic vibrations are beingapplied thereto, and subsequently cutting the Au wires from portions ofthe balls to thereby form bumps. Thus the stud bumps formed on theelectrode pads are firmly connected to their corresponding electrodepads.

[0064] As shown in FIG. 3, the control chip 10 is mounted in a state inwhich its circuit forming surface 10X is placed face-to-face with onemain surface 2X of the wiring board 2. For instance, an anisotropicconductive resin 20 is interposed between each buffer chip 14 and thewiring board 2 as a bonding or adhesive resin. The control chip 10 isbonded and fixed to the wiring board 2 by means of the anisotropicconductive resin 20.

[0065] The stud bumps 11 of the control chip 10 are respectively placedbetween the electrode pads 10 a of the control chip 10 and theconnecting portions 3 placed on the wiring board 2 through the openingsdefined in the insulating film 5 to thereby electrically connect thetwo. The stud bumps 11 are pressure-welded to their correspondingconnecting portions 5 a of the wiring board 2 by a heat shrinkage force(corresponding to a contractile or shrinkage force produced when theanisotropic conductive resin 20 is restored from a heated state to aroom-temperature state) of the anisotropic conductive resin 20interposed between the wiring board 2 and the control chip 10, and athermosetting shrinkage force (corresponding to a contractile orshrinkage force produced when a thermosetting resin is cured), acrimping force developed by a thermo-compression bonding tool, etc.Parts of conductive particles mixed into the anisotropic conductiveresin 20 in large quantities are respectively interposed between thestud bumps 11 and the connecting portions 5 a of the wiring board 2.Incidentally, the memory chips 12, the buffer chips 14 and the operationchip 16 are also packaged or mounted in a manner similar to the controlchip 10.

[0066] Each of the chip capacitors 17 is shaped in the form of arectangle and has electrode portions 17 a at their both ends. The chipcapacitors 18 and the chip resistors 19 are also configured in a mannersimilar to the chip capacitors 17. The chip capacitors 17 and 18 and thechip resistors 19 are electrically and mechanically connected to theircorresponding electrode pads 4 of the wiring board 2 by solder 21through the openings defined in the insulating film 5.

[0067] Heights (corresponding to heights from one main surface 2X of thewiring board 2 to the top portions of the post-mounting electroniccomponents) of the post-mounting respective electronic components are asfollows.

[0068] The heights of the control chip 10 and the memory chip 12 areabout 0.4 [m], the heights of the buffer chip 14 and the operation chip16 are about 0.28 [m], the height of each chip capacitor 17 is about0.85 [m], the height of each chip capacitor 18 is about 0.8 [m], and theheight of each chip resistor 19 is about 0.45 [m], respectively.

[0069] The manufacture of the MCM 1 will next be explained withreference to FIGS. 4 through 9. FIGS. 4 through 7 are respectivelytypical cross-sectional views for describing a process for the MCM, andFIGS. 8 and 9 are respectively typical plan views for describing theprocess for the MCM. Incidentally, hatching indicative of sections areomitted in FIGS. 4 through 7 to make it easy to see the drawings.

[0070] As the present embodiment, a description will be made of anembodiment in which soldering electronic components are mounted afterthe mounting or packaging of compression mounted electronic components.

[0071] The compression mounted electronic components (corresponding tothe control chip 10, memory chips 12, buffer chips 14 and operation orarithmetic chip 16) and the soldering electronic components(corresponding to the chip capacitors 17 and 18 and chip resistors 19)are first prepared, and a wiring board 2 shown in FIG. 4(A) is prepared.Stud pads 11 have been formed on their corresponding electrode pads ofthe control chip 10, memory chips 12, buffer chips 14 and operation chip16.

[0072] Next, as shown in FIG. 4(B), a sheet-shaped anisotropicconductive resin film 20A is transferred from a cover tape 23 to itscorresponding control chip mounting or loading area of one main surfaceof the wiring board 2 by means of an applying or sticking tool (stickinghead) 25. As shown in FIG. 5(A), the anisotropic conductive resin film20A is placed on its corresponding control chip mounting area of onemain surface 2X of the wiring board 2. As the anisotropic conductiveresin film 20A, one is used which is obtained by mixing lots ofconductive particles into an epoxy thermosetting resin, for example.

[0073] Next, as shown in FIG. 5(B), the corresponding control chip 10 isplaced on its corresponding control chip mounting area of one mainsurface 2X of the wiring board 2 with the anisotropic conductive resinfilm 20A interposed therebetween. The control chip 10 is placed in sucha manner that its circuit forming surface 10X is provided face to facewith one main surface 2X of the wiring board 2. The control chip 10 isconveyed from a storage tray to the control chip mounting area of onemain surface 2X of the wiring board 2 by means of a conveying collet ofa chip loader.

[0074] Next, as shown in FIG. 6(A), the control chip 10 isthermo-compression bonded by a thermo-compression bonding tool 26A toconnect the stud bumps 11 to their corresponding connecting portions 3of the wiring board 2. Thereafter, its thermo-compression bonded stateis held until the anisotropic conductive resin film 20A is cured. Ananisotropic conductive resin film 20A is melted once and thereaftercured. Thus, as shown in FIG. 6(B), the control chip 10 is bonded andfixed to the wiring board 2 by the cured anisotropic conductive resin20. Electrode pads 10 a of the control chip 10 are pressure-welded totheir corresponding connecting portions 3 of the wiring board 2 andthereby electrically connected to the connecting portions 3 of thewiring board 2 through the stud bumps 11 and parts of the conductiveparticles mixed into the anisotropic conductive resin 20 in largequantities. In the present process, the thermo-compression bonding ofthe chip is carried out with a Teflon sheet 24 interposed between thecontrol chip 10 and the thermo-compression bonding tool 26A.

[0075] Next, each of the memory chips 12 is implemented on itscorresponding memory chip mounting area of one main surface 2X of thewiring board 2 by a method similar to the control chip 10. Thereafter,each of the buffer chips 14 is mounted on its corresponding buffer chipmounting area of one main surface 2X of the wiring board 2 by the methodsimilar to the control chip 10. Subsequently to it, the operation chip16 is implemented on its corresponding operation chip mounting area ofone main surface 2X of the wiring board 2 by the method similar to thecontrol chip 10. Thus, as shown in FIG. 8, compression mounted orpackaged components are placed on one main surface 2X of the wiringboard 2.

[0076] When the soldering electronic components high in post-packageheight as compared with the compression mounted electronic componentsare mounted prior to the mounting of the compression mounted electroniccomponents, the thermo-compression bonding tool 26A forthermo-compression bonding the compression mounted electronic componentsbecome easy to contact the already-mounted soldering components. It istherefore necessary to widen the interval between each solderingelectronic component and its corresponding compression mountedelectronic component. However, the mounting of the compression mountedelectronic components prior to the soldering electronic components as inthe present embodiment makes it possible to substantially eliminate theproblem that the thermo-compression bonding tool 26A makes contact withthe soldering components. It is therefore possible to narrow theinterval between the soldering electronic component and itscorresponding compression mounted electronic component.

[0077] In the present embodiment as well, the curing of the anisotropicconductive resin film 20A is carried out under the condition of 180° C.and 20 seconds. Heating at this time is carried out by thethermo-compression bonding tool 26A heated to 235° C. after thetemperature of the wiring board 2 has been set to 65° C. in advance.When the curing of the anisotropic conductive resin film 20A is carriedout under the condition of 200° C. and 10 seconds to achieve a furtherimprovement in productivity as compared with the condition for thethermo-compression bonding process, it is necessary to increase the settemperature of the thermo-compression bonding tool 26A to 265° C. whilethe temperature of the wring board 2 is being kept at 65° C. as it is.

[0078] When the processing temperature for the thermo-compressionbonding process is higher than a melting point (183° C., for example) ofsolder adopted as a soldering paste material 21A, solder for eachsoldering component might be melted by heat in the thermo-compressionbonding process if the soldering electronic components are mounted priorto the compression mounted electronic components. There is a possibilitythat when a thermo-compression bonding tool 26A having such a size as tocover the area for mounting the soldering electronic components isadopted in particular, solder will melt even where the post-mountingheight of each soldering electronic component is higher or lower thanthat the post-mounting height of each compression mounted electroniccomponent, thereby causing problems such as the omission of eachsoldering electronic component, etc. However, when the compressionmounted electronic components are mounted prior to the solderingelectronic components as described in the present embodiment, heattreatment in the thermo-compression bonding process is in no danger ofexerting a bad influence on the soldering electronic components.Further, the heat in the process of melting the soldering paste material21A is at low risk of exerting a bad influence on the anisotropicconductive resin 20 whose curing has been finished. Thus, anadvantageous effect is brought about in that owing to the mounting ofthe compression mounted electronic components prior to the solderingelectronic components, a large thermo-compression bonding tool 26Acapable of being adopted even for a process for thermo-compressionbonding a large chip and a process for collectively thermo-compressionbonding a plurality of chips can commonly be adopted even for a processfor thermo-compression bonding a small chip.

[0079] When it is desired to collectively thermo-compression bond aplurality of compression mounted electronic components to achieve animprovement in productivity, it is necessary to use a thermo-compressionbonding head larger than the compression mounted electronic components.If soldering electronic components high in height exist within a rangefor a bonding tool in such a case, it is difficult to collectivelythermo-compression bond them. However, the mounting of the compressionmounted electronic components prior to the soldering electroniccomponents allows the collective thermo-compression bonding of theplurality of compression mounted electronic components.

[0080] When the thermo-compression bonding tool 26A larger than at leastthe compression mounted electronic components is adopted as described inthe present embodiment, a Teflon sheet 24 can be interposed between eachof the compression mounted electronic components and thethermo-compression bonding tool 26A to prevent the thermo-compressionbonding tool 26A from being contaminated due to the anisotropicconductive resin 20 that extends out toward the periphery of eachcompression mounted electronic component.

[0081] Next, a soldering paste material 21A is supplied onto eachelectrode pad 4 in one main surface 2X of the wiring board 2. The supplyof the soldering paste material 21A is carried out by a dispenser methodfor discharging the soldering paste material 21A from a thin nozzle 27and applying it to each electrode pad as shown in FIG. 7(A). As thesoldering paste material 21A, a soldering paste material is used whichis obtained by blending and kneading at least fine solder particles andflux. In the present embodiment, a soldering paste material obtained bymixing and kneading solder particles each having a 37[wt %]Pb-63[wt %]Sncomposition, for example is used. Incidentally, the flux may include apine resin, an active material and an organic solvent or the like.

[0082] Next, as shown in FIG. 7(B), chip capacitors 17 and 18 and chipresistors 19 are placed on their corresponding electrode pads 4 of onemain surface 2X of the wiring board 2 with the soldering paste material21A interposed therebetween. Afterwards, heat treatment is done to meltthe soldering paste material 21A, whereby as shown in FIG. 3, theelectrode pads 4 on the wiring board 2 and the electrodes 17A of thechip capacitors 17 are electrically and mechanically connected to oneanother by means of solder 21, and the electrode pads 4 on the wiringboard 2 and the electrodes for the chip capacitors 18 and the chipresistors 19 are also electrically and mechanically connected to oneanother by the solder 21 in a manner similar to the chip capacitors 17.Thus, as shown in FIG. 9, the soldering electronic components are placedon one main surface 2X of the wiring board 2.

[0083] In the process for melting the soldering paste material 21A, theperiphery of each soldering electronic component is contaminated by thecomposition of the flux contained in the soldering paste material 21A.However, the mounting of the compression mounted electronic componentsprior to the soldering electronic components makes it possible toprevent the respective connecting portions 3 of the wiring board 2connected to the compression mounted electrode components from beingcontaminated by the flux composition.

[0084] According to the present embodiment as described above, thefollowing advantageous effects are obtained.

[0085] (1) The soldering electronic components high in post-mountingheight as compared with the compression mounted electronic componentsare mounted or packaged prior to the compression mounted electroniccomponents. Thus, since it is possible to substantially eliminate theproblem that the thermo-compression bonding tool 26A makes contact withthe soldering electronic components, the intervals between the solderingelectronic components and the compression mounted electronic componentscan be narrowed respectively. As a result, the MCM 1 can be reduced insize.

[0086] Owing to the implementation or packaging of the compressionmounted electronic components prior to the soldering electroniccomponents, the large thermo-compression bonding tool 26A capable ofbeing adopted even for the process for thermo-compression bonding thelarge chip and the process for collectively thermo-compression bondingthe plurality of chips can commonly be adopted even for the process forthermo-compression bonding each small chip.

[0087] Since the plurality of compression mounted electronic componentscan collectively be thermo-compression bonded, an improvement inproductivity of the MCM 1 can be achieved.

[0088] When the thermo-compression bonding tool 26A larger than at leastthe compression mounted electronic component is adopted, the Teflonsheet 24 can be interposed between each of the compression mountedelectronic components and the thermo-compression bonding tool 26A toprevent the thermo-compression bonding tool 26A from being contaminatedby the anisotropic conductive resin 20 that extends out toward theperiphery of each compression mounted electronic component. As a result,an improvement in productivity of the MCM 1 can be achieved.

[0089] Mounting the compression mounted electronic components prior tothe soldering electronic components makes it possible to prevent therespective connecting portions 3 of the wiring board 2 connected to thecompression mounted electrode components from being contaminated by theflux composition. As a result, an improvement in productivity of the MCM1 can be achieved.

[0090] (2) The supply of the soldering paste material 21A is carried outby the dispenser method. Thus, since the soldering paste material 21Acan be supplied onto the electrode pads 4 of the wiring board 2 evenafter the mounting of the compression mounted electronic components, thesoldering electronic components can be implemented or packaged evenafter the implementation of the compression mounted electroniccomponents.

[0091] The supply of the soldering paste material 21A subsequent to themounting of the compression mounted electronic components can be carriedout even by a screen printing method using an embossed mask. In such acase, however, it is difficult to place each of the soldering electroniccomponents in the neighborhood (about 5 mm or less) of the compressionmounted electronic component. Accordingly, the supply of the solderingpaste material by the dispenser method is advantageous to achieve a sizereduction in MCM 1. On the other hand, when semiconductor devices suchas multi-pin BGA, CSP, QFP and QFN types, etc. are installed assoldering electronic components, the number of points to supply thesoldering paste material increases. It is therefore disadvantageous tosupply the soldering paste material by the dispenser method. When suchmulti-pin semiconductor devices are packaged or implemented, the supplyof the soldering paste material by the screen printing method using theembossed mask is advantageous.

[0092] As a second embodiment, a description will be made of anembodiment wherein upon the manufacture of an MCM, compression mountedcomponents are implemented after the mounting of soldering mountedcomponents.

[0093]FIGS. 10 through 15 are respectively cross-sectional views fordescribing the manufacture of the MCM showing the second embodiment ofthe present invention. FIGS. 16 and 17 are respectively plan views fordescribing the manufacture of the MCM showing the second embodiment ofthe present invention. Incidentally, hatching indicative of sections areomitted in FIGS. 10 through 15 to make it easy to see the drawings.

[0094] Compression mounted parts or components (control chip 10, memorychips 12, buffer chips 14 and arithmetic or operation chip 16) andsoldering mounted parts or components (chip capacitors 17 and 18 andchip resistors 19) are first prepared. Further, a wiring board 2 shownin FIG. 10(A) is prepared. Stud bumps 11 are formed on theircorresponding electrode pads of the control chip, 10, memory chips 12,buffer chips 14 and operation chip 16.

[0095] Next, a screen mask 28 is placed on one main surface 2X of thewiring board 2. The screen mask 28 has apertures or openings 28A atpositions opposite to the respective pads 4 on the wiring board 2.

[0096] Next, a semisolid soldering paste material (cream solder) 21A isapplied onto one surface of the screen mask 28. As the soldering pastematerial 21A, a soldering paste material is used which is obtained bymixing and kneading at least fine solder particles and flux. In thepresent embodiment, a soldering paste material obtained by mixing andkneading solder particles each having a 37[wt %]lead (Pb)-63[wt %]tin(Sn) composition, for example is used. Incidentally, the flux mayinclude a pine resin, an active material and an organic solvent or thelike.

[0097] Next, s shown in FIG. 10(B), a squeegee 29 is slid along onesurface of the screen mask 28 to charge the soldering paste material 21Ainto the openings 28A of the screen mask 28 and remove the extrasoldering paste material 21A. The sliding of the squeegee 29 is carriedout a few times. Thereafter, the screen mask 28 is removed so that thesoldering paste material 21A is supplied onto the respective electrodepads 4 on the wiring board 2 by a screen printing method as shown inFIG. 11(A). The collective supply of the soldering paste material 21Aonto the respective electrode pads 4 on the wiring board 2 by the screenprinting method in this way is advantageous to the mounting ofsemiconductor devices such as multi-pin BGA, CSP, QFP and QFN types,etc. as compared with the case in which the soldering paste material 21Ais supplied to each individual electrode pads 4 by, for example, adispense method or the like.

[0098] Next, as shown in FIG. 11(B), chip capacitors 17 and 18 and chipresistors 19 are placed on their corresponding electrode pads 4 of onemain surface 2X of the wiring board 2 with the soldering paste material21A interposed therebetween. Afterwards, heat treatment is done to meltthe soldering paste material 21A, whereby as shown in FIG. 12(A), theelectrode pads 4 on the wiring board 2 and electrodes 17A of the chipcapacitors 17 are electrically and mechanically connected to one anotherby means of solder 21, and the electrode pads 4 on the wiring board 2and electrodes for the chip capacitors 18 and the chip resistors 19 arealso electrically and mechanically connected to one another by thesolder 21 in a manner similar to the chip capacitors 17. Thus, as shownin FIG. 16, the soldering electronic components are placed on one mainsurface of the wiring board 2.

[0099] Next, as shown in FIG. 12(B), respective connecting portions 3 ofthe wiring board 2 are cleaned by plasmas P prior to the mounting of thecompression mounted components (plasma cleaning). Thus the plasmacleaning makes it possible to perfectly remove contamination developeddue to the composition of flux in the soldering paste material 21A andprevent failures in connections between the stud pads 11 and therespective connecting portions 3 of the wiring board 2.

[0100] Next, as shown in FIG. 13(A), a sheet-shaped anisotropicconductive resin film 20A is transferred from a cover tape 23 to itscorresponding control chip mounting or loading area of one main surfaceof the wiring board 2 by means of an applying or sticking tool 25. Asshown in FIG. 13(B), the anisotropic conductive resin film 20A is placedon its corresponding control chip mounting area of one main surface 2Xof the wiring board 2. As the anisotropic conductive resin film 20A, oneis used which is obtained by mixing lots of conductive particles into anepoxy thermosetting resin, for example.

[0101] Next, as shown in FIG. 14(A), the control chip 10 is placed onits corresponding control chip mounting area of one main surface 2X ofthe wiring board 2 with the anisotropic conductive resin film 20Ainterposed therebetween. The control chip 10 is placed in such a mannerthat its circuit forming surface 10×is provided face to face with onemain surface 2X of the wiring board 2. The control chip 10 is conveyedfrom a storage tray to the control chip mounting area of one mainsurface 2X of the wiring board 2 by means of a conveying collet of achip loader.

[0102] Next, as shown in FIG. 14(B), the control chip 10 isthermo-compression bonded by a thermo-compression bonding tool 26B toconnect the stud bumps 11 to their corresponding connecting portions 3of the wiring board 2. Thereafter, its thermo-compression bonded stateis held until the anisotropic conductive resin film 20A is cured. Theanisotropic conductive resin film 20A is melted once and thereaftercured. Thus, as shown in FIG. 15, the control chip 10 is bonded andfixed to the wiring board 2 by the cured anisotropic conductive resin20. Electrode pads 10 a of the control chip 10 are pressure-welded totheir corresponding connecting portions 3 of the wiring board 2 andthereby electrically connected to the connecting portions 3 of thewiring board 2 through the stud bumps 11 and parts of the conductiveparticles mixed into the anisotropic conductive resin 20 in largequantities.

[0103] Next, each of the memory chips 12 is implemented on itscorresponding memory chip mounting area of one main surface of thewiring board 2 by a method similar to the control chip 10. Thereafter,each of the buffer chips 14 is mounted on its corresponding buffer chipmounting area of one main surface 2X of the wiring board 2 by the methodsimilar to the control chip 10. Subsequently to it, the operation chip16 is implemented on its corresponding operation chip mounting area ofone main surface 2X of the wiring board 2 by the method similar to thecontrol chip 10. Thus, as shown in FIGS. 15 and 17, compression mountedor packaged components are placed on one main surface 2X of the wiringboard 2.

[0104] When the soldering electronic component is mounted prior to thecompression mounted electronic component, it is necessary to adopt onesmall to such an extent that a thermo-compression bonding tool 26B nointerferes with the soldering electronic component, as thethermo-compression bonding tool 26B. Owing to the use of one wherein ahead surface of the thermo-compression bonding tool 26B is smaller thanthe compression mounted electronic component to be thermo-compressionbonded in particular, the thermo-compression bonding tool 26B can beprevented from being contaminated by the anisotropic conductive resin 20that has extended out toward the periphery of the compression mountedelectronic component.

[0105] Further, since the upper portions of all the stud bumps arecovered with the head surface of the thermo-compression bonding tool 26Bwhere the head surface of the thermo-compression bonding tool 26B issmaller than the compression mounted electronic component, the peripheryof the head surface of the thermo-compression bonding tool 26B is set soas to be located between the stud bumps and the periphery of thecompression mounted electronic component in an on-plane layout.Consequently, all of heat and pressure applied by the thermo-compressionbonding tool 26B can more uniformly be applied to all the stud bumps.

[0106] According to the present embodiment as described above, thefollowing advantageous effect are obtained.

[0107] (1) Since the soldering paste material 21A can be suppliedaccording to the normal screen printing method owing to the mounting ofthe soldering electronic components prior to the compression mountedelectronic components, the MCM can be downsized as compared with thecase where the soldering paste material 21A is supplied by the screenprinting method using the embossed mask. Further, the productivity ofthe MCM can be improved as compared with the case in which the solderingpaste material 21A is supplied by the dispenser method.

[0108] (2) Owing to the use of the head surface of thethermo-compression bonding tool 26B, which is smaller than eachcompression mounted electronic component to be thermo-compression bondedin the embodiment wherein the soldering electronic components aremounted prior to the compression mounted electronic component, thethermo-compression bonding tool 26B can be prevented from beingcontaminated by the anisotropic conductive resin 20 that has extendedout toward the periphery of the compression mounted electroniccomponent. As a result, the productivity of the MCM can be improved.

[0109] (3) In the embodiment in which the soldering electroniccomponents are implemented prior to the compression mounted electroniccomponents, the periphery of the head surface of the thermo-compressionbonding tool 26B is set so as to be located between the stud bumps andeach of the compression mounted electronic components. Consequently, allof heat and pressure applied by the thermo-compression bonding tool 26Bcan more uniformly be applied to all the stud bumps.

[0110] (4) Since the connecting portion 3 of the wiring board 2, whichhas been contaminated by the flux or the like of the soldering pastematerial 21A can be cleaned by execution of plasma screening before themounting of each compression mounted electronic component, it ispossible to control or restrain failures in electrical connectionsbetween the compression mounted electronic component and the connectingportions 3 of the wiring board 2. As a result, the enhancement of yieldsof the MCM can be achieved.

[0111] (5) One smaller than each compression mounted electroniccomponent to be thermo-compression bonded is used as thethermo-compression bonding tool to thereby make it possible to avoid thecontact between the already-mounted soldering electronic component andthe thermo-compression bonding head.

[0112] Incidentally, the first and second embodiments respectively havedescribed the example in which the stud bumps are used as the protrudedelectrodes formed on the electrode pads of the semiconductor chip.However, the present invention is not limited to the above. Forinstance, solder bumps each having a Pb—Sn composition may be used.However, solder bumps are used, each of which comprises a material whosemelting point is higher than a solder melting temperature at themounting of each soldering electronic component and a thermo-compressionbonding temperature at the mounting of each compression mountedelectronic component.

[0113] While the first and second embodiments respectively havedescribed the example in which the protruded electrodes interposedbetween the electrode pads of the compression mounted electroniccomponents and their corresponding connecting portions of the wiringboard are formed on their corresponding electrode pads of thecompression mounted electronic component in advance, the protrudedelectrodes may be formed on their connecting portions of the wiringboard in advance.

[0114] Further, while the first and second embodiments respectively havedescribed the example in which the sheet-like conductive resin is usedas the bonding resin for bonding and fixing each compression mountedelectronic component to the wiring board. However, the present inventionis not limited to the above. For example, a paste-like anisotropicconductive resin (ACP) and a sheet-like non-conductive resin (NCF) maybe used.

[0115] As a third embodiment, a description will be made of an MCM towhich a radiator is attached.

[0116]FIG. 18 is a cross-sectional view of the MCM showing the thirdembodiment of the present invention, and FIGS. 19 and 20 arerespectively developed views of the MCM shown in FIG. 18. Incidentally,hatching indicative of a section in FIG. 18 is omitted to make it easyto see the drawing.

[0117] As shown in FIGS. 18 through 20, the MCM according to the presentembodiment is configured so as to have a thermal conductive sheet 30 anda radiator 31. The thermal conductive sheet 30 is formed of elastomericsilicon rubber, for example, and the radiator 31 is formed of a planeplate made up of aluminum, for example.

[0118] The thermal conductive sheet 30 has a shape patterned so as tomake contact with the back of each compression mounted electroniccomponent and not to make contact with chip capacitors 17 and 18. Thethermal conductive sheet 30 having such a shape is mounted to the backof each compression mounted electronic component, and the radiator 31 ismounted to the thermal conductive sheet 30, whereby the difference invertical interval between the compression mounted electronic componentand each of the chip capacitors 17 and 18 can be complemented with thethickness of the thermal conductive sheet 30. Therefore, the chipcapacitors 17 and 18 high in height do not interfere with the contactbetween the compression mounted electronic component and the thermalconductive sheet 30 as shown in FIG. 21. As a result, heat generatedupon the operation of the compression mounted electronic component canefficiently be transferred to the thermal conductive sheet 30, and hencethe dissipation of the MCM can be improved.

[0119] The radiator 31 is formed so as to cover a plurality ofcompression mounted electronic components and a plurality of solderingelectronic components, and in a plane size larger than that of thethermal conductive sheet 30, whereby the radiator 31 increases in area,thus making it possible to achieve a further improvement in dissipationof the MCM.

[0120] Further, the thermal conductive sheet 30 has such a shape as tomake contact with each of chip resistors 19A. This is because theheights of the control chip 10 and each memory chip 12 placed on bothsides of the chip resistor 19A are 0.4 [m], whereas the height of thechip resistor 19A is 0.45 [m], and the difference in vertical heighttherebetween is equivalent to such an extent as that it is capable ofbeing accommodated according to the deformation of the thermalconductive sheet 30. Owing to the selective placement of ones relativelylow in post-mounting height even in soldering components within anapplying or sticking area of the thermal conductive sheet 30 in thisway, the area between the adjacent compression mounted electroniccomponents can also be effectively utilized, and the MCM can bedownsized.

[0121] While the invention made above by the present inventors has beendescribed specifically by the illustrated embodiments, the presentinvention is not limited to the embodiments. It is needless to say thatvarious changes can be made thereto within the scope not departing fromthe substance thereof.

[0122] Advantageous effects obtained by typical ones of the inventionsdisclosed in the present application will be described in brief asfollows:

[0123] According to the present invention, the productivity of anelectronic device can be improved.

[0124] According to the present invention, an electronic device can bebrought into less size.

[0125] According to the present invention, the dissipation of anelectronic device can be enhanced.

1. A method of manufacturing an electronic device including: a first electronic component mounted on one main surface of a wiring board by being thermo-compression bonded by means of a thermo-compression bonding tool with an adhesive resin interposed between a first area of the one main surface of the wiring board and said first electronic component; and a second electronic component mounted on a second area different from the first area of the one main surface of the wiring board by melting a soldering paste material and higher than said first electronic component in post-mounting height, said method comprising the step of: mounting said first electronic component before the mounting of said second electronic component.
 2. The method according to claim 1, wherein the adhesive resin is a thermosetting resin.
 3. The method according to claim 1, wherein the temperature of the thermo-compression bonding tool at the time that the first electronic component is thermo-compression bonded, is higher than a melting point of the soldering paste material.
 4. The method according to claim 1, wherein said first electronic component is an active part with circuits built therein, and wherein said second electronic component is a passive part.
 5. A method of manufacturing an electronic device, comprising the following steps: a first step of placing a first electronic component on a first area of one main surface of a wiring board with an adhesive resin interposed therebetween, thereafter thermo-compression bonding the first electronic component by a thermo-compression bonding tool, bonding and fixing the first electronic component to the first area of the one main surface of the wiring board, and electrically connecting first connecting portions provided in the first area of the one main surface of the wiring board and electrode pads provided in the first electronic component by protruded electrodes interposed therebetween, respectively; and a second step of supplying a soldering paste material to second connecting portions provided in a second area different from the first area of the one main surface of the wiring board, thereafter placing electrodes of a second electronic component on the second connecting portions with the soldering paste material interposed therebetween, respectively, and subsequently melting the soldering paste material to thereby electrically connect the second connecting portions of the wiring board and the electrodes of the second electronic component respectively, wherein said first step is executed before the execution of said second step.
 6. The method according to claim 5, wherein said second electronic component has a height extending from the one main surface of the wiring board to the top portion, which is higher than that of the first electronic component.
 7. The method according to claim 5, wherein said adhesive resin is a thermosetting resin.
 8. The method according to claim 5, wherein the temperature of the thermo-compression bonding tool at the time that the first electronic component is thermo-compression bonded, is higher than a melting point of the soldering paste material.
 9. The method according to claim 5, wherein the supply of the soldering paste material is carried out by a dispense method.
 10. A method of manufacturing an electronic device including a first electronic component mounted on one main surface of a wiring board by being thermo-compression bonded by means of a thermo-compression bonding tool with an adhesive resin interposed between a first area of the one main surface of the wiring board and said first electronic component, and a second electronic component mounted on a second area different from the first area of the one main surface of the wiring board by melting a soldering paste material, said method comprising the steps of: mounting said second electronic component before the mounting of said first electronic component.
 11. The method according to claim 10, wherein the supply of the soldering paste material is carried out by a screen printing method.
 12. The method according to claim 10, wherein said second electronic component is higher than said first electronic component in post-mounting height.
 13. The method according to claim 10, wherein said first electronic component is an active part with circuits built therein, and wherein said second electronic component is a passive part.
 14. A method of manufacturing an electronic device, comprising the steps: a first step of placing a first electronic component on a first area of one main surface of a wiring board with an adhesive resin interposed therebetween, thereafter thermo-compression bonding the first electronic component by a thermo-compression bonding tool, bonding and fixing the first electronic component to the first area of the one main surface of the wiring board, and electrically connecting first connecting portions provided in the first area of the one main surface of the wiring board and electrode pads provided in the first electronic component by protruded electrodes interposed therebetween, respectively; and a second step of supplying a soldering paste material to second connecting portions provided in a second area different from the first area of the one main surface of the wiring board, thereafter placing electrodes of a second electronic component on the second connecting portions with the soldering paste material interposed therebetween, respectively, and subsequently melting the soldering paste material to thereby electrically connect the second connecting portions of the wiring board and the electrodes of the second electronic component respectively, wherein said second step is executed before the execution of said first step.
 15. An electronic device comprising: a first electronic component bonded and fixed to a first area of one main surface of a wiring board with an adhesive resin interposed therebetween, and having electrode pads respectively electrically connected to first connecting portions provided in the first area of the one main surface of the wiring board with protruded electrodes being interposed therebetween; and a second electronic component fixed to a second area different from the first area of the one main surface of the wiring board, and having electrodes respectively electrically connected to second connecting portions provided in the second area of the one main surface of the wiring board with soldering materials being interposed therebetween.
 16. An electronic device comprising: a wiring board; a plurality of first electronic components implemented in a first area of one main surface of the wiring board; a plurality of second electronic components implemented in a second area different from the first area of the one main surface of the wiring board, and each having a height extending from the one main surface of the wiring board to the top portion, which is higher than that of said each first electronic component; and a thermal conductive sheet mounted to said plurality of first electronic components and dismounted to said plurality of second electronic components.
 17. The electronic device according to claim 16, further including a radiator mounted to said thermal conductive sheet and formed in a flat size for covering said plurality of first electronic components and said plurality of second electronic components.
 18. The electronic device according to claim 16, wherein said plurality of second electronic components are smaller than said plurality of first electronic components in the amount of heat generated during operation.
 19. The electronic device according to claim 16, wherein said plurality of first electronic components are semiconductor chips with circuits built therein, and wherein said plurality of second electronic components are active parts.
 20. The method according to claim 10, wherein a surface for thermo-compression bonding said first electronic component by said thermo-compression bonding tool is smaller than said first electronic component in width.
 21. The method according to claim 14, wherein a surface for thermo-compression bonding said first electronic component by said thermo-compression bonding tool is smaller than said first electronic component in width. 